Evolution

1. is the change in the inherited traits of a population of organisms through successive generations Evolution

2. Spontaneous Generation or Abiogenesis • Living matter arose from non-living matter. • Example –creek created fish, bees from flowers Biogenesis – living things arise from other living things.

3. Experiments proving biogenesis • Redi – (1600s) flies from other flies not meat • Needham – (1700s) experimented with heated gravy and concluded that the microscopic organisms that appeared were the result of spontaneous generation • Spallanzani – (1700s) experimented with Needham's gravy to show that the microscopic organisms entered from the air, not by means of spontaneous generation • Pasteur – (1864) proved biogenesis by using a curved flask

4. Redi Proved that flies come from other flies that lay eggs on the meat.

5. Needham .He boiled chicken broth for a short period of time, put it into a flask, sealed it, and waited and microorganisms grew. Needham said that their was a “vital force” in the air and claimed a victory for spontaneous generation.

6. Spallanzani Tested spontaneous generation of microorganisms. Proved that they did not appear from air but came from other microorganisms. Scientists claimed that he destroyed the “vital force” by boiling the flask.

7. Pasteur Made a curved neck flask that allowed air to enter – the microorganisms collected in the curve, after one year it was still clear. Then he broke the flask and was cloudy within one day. Proving that microorganisms are everywhere – even in the air – finally proving biogenesis.

8. Origin of Life on Earth • The atmosphere was harsh- • Methane gas, volcanic eruptions and lightning storms. • Meteorites bombarding the surface. • Molten rock and very hot temperatures. • Then it cooled and water vapor fell to the earth to make the oceans.

9. Primordial soup • is the mix of gases in water that were present at the time of primitive earth that when electrically charged created basic organic molecules. • such as amino acids- the basic building blocks for proteins, that eventually led to the formation and creation of life on Earth.

10. First Forms of Life • Prokaryotes – ancient anaerobic bacteria that were heterotrophic (used the chemicals for food) • Then because of competition other prokaryotes evolved that were autotrophic and made their own food.

11. First Eukaryotes • Developed through a theory called: endosymbiosis Some prokaryotes lived inside other prokaryotes and eventually lost the ability to move in and out of the cell – this formed the organelles in the eukaryotic cells.

12. Scientific Evidence for Evolution • Comparing Fossils to Living organisms

13. Common Ancestry Even though they live in different areas they have the same structures.

14. Homologous structures Contain similar anatomical traits.

15. Vestigial Organs • Organs that have no apparent function. (useless)

16. Biochemistry • Certain chemicals found in organisms • Type of blood proteins • Amino acid sequences

17. Embryological Development • Similarities in developing embryos.

18. Evolution theories before Darwin • Lamarck – acquired or learned traits are passed from parent to offspring.

19. Charles Darwin • 1809-1882 • Enjoyed observing nature • Went to medical school at 16 didn’t like that – dropped out • He was chosen to be the naturalist on the ship the Beagle. (a 5 year mapping expedition) • He collected specimens, made observations and kept records of anything he thought was important.

20. His greatest findings were • From the Galapagos Islands

21. Famous for finches Darwin inferred that the finches had a common ancestor

22. Theory of Natural Selection • Individuals that have advantageous variations (traits) will more likely survive and reproduce than those without the advantageous traits. • The organisms adapted to it’s surroundings • The “Origin of Species” was a book by Darwin that explained natural selection. http://geowords.org/ensci/imagesbook/03_03_moth_change.swf

23. Natural Selection video • http://www.teachersdomain.org/resource/tdc02.sci.life.evo.howreally/

24. Interactive Evolution Game • http://science.discovery.com/interactives/literacy/darwin/darwin.html

25. Patterns of Evolution • Adaptive Radiation – when many related species evolved from a single ancestral species. Called speciation. • Speciation is the process by which new distinct species evolve. • Examples: • Divergent evolution • Convergent evolution • Coevolution

26. Divergent Evolution • 2 or more related species become dissimilar • Scientists think that a group of brown bears became separated from the others and adapted to a colder environment.

27. Convergent Evolution • Unrelated species become more similar in appearance as they adapt to their environment. • These 2 different plants look similar because they have adapted to conserve water while living in a dry environment.

28. Convergent evolution cont. • Analogous structures – traits that are similar due to evolution • Example fins in a dolphin and fins in a fish Whale is a mammal This is a fish

29. Coevolution • Is the joint change of 2 or more species in close interaction.

30. Speciation explanation • http://schools.birdvilleschools.net/17862081410486910/lib/17862081410486910/archipelago.swf

31. What causes organisms to evolve? • Gene flow – movement of genes from one population to another (body color) • Sexual reproduction – shuffles genes which introduces new variations • Adjustments to a changing environment • Too hot, too cold, not enough resources • Mutations in DNA due to errors in replication • External influences – chemicals or radiation • Natural selection- favorable traits • Geographic isolation – some organisms are separated from the population